You’ve seen the shocking photos of Matthew McConaughey, who dropped more than 40 pounds to play Ron Woodroof, the real-life AIDS patient in Dallas Buyers Club. But McConaughey isn’t the only star of the film who underwent a complete physical transformation. Jared Leto plays Rayon, the HIV-positive transsexual who becomes Ron’s business partner in their 1980s drug-smuggling operation to get unapproved AIDS medicines into the U.S. Leto not only dropped more than 30 pounds to play the dying drug addict – a feat he’d famously done before for Requiem for a Dream – but he stayed in-character as Rayon for the entire production of the film. “Every morning, when I stepped out of that van that took us to set, I always had my high-heels on,” says Leto. “It kind of set the clock.”

Rock fans might know Leto best as the lead singer of Thirty Seconds to Mars, since he hadn’t acted in more than five years while the band toured the world and he focused on making music, directing videos, and making documentaries. But anyone who got the joke at the end of the recent Audi commercial starring Claire Danes knows that Leto was famously the teenage heartthrob in the shortlived TV series My So-Called Life. After notable roles in Prefontaine, Requiem, Panic Room, and Lord of War, Leto focused more on his band, but Dallas Buyers Club offered the right role at the right time. “He always talked about an interest in playing a transgender,” says Leto’s brother, Shannon, drummer for 30 Seconds to Mars. “He’s just an artist. He does many things. I thought the role was great, so it was like, of course you’re going to do that role. I was happy for him.”

After premiering at the Toronto Film Festival, Dallas Buyers Club and its two actors have catapulted into the Oscar conversation. For McConaughey, a nomination could be the culmination of an amazing two-year stretch of critically-embraced roles that have completely remade his career. For Leto, it might be the beginning of a new chapter in his life as an actor. “I’m still in a daze from Toronto,” he says. “I think you can call it a career-altering experience. Maybe a life-changing one, we’ll see.”

Click below for an interview with Leto, and be sure to read this week’s Entertainment Weekly for more about Jared Leto and Dallas Buyers Club.

ENTERTAINMENT WEEKLY: You lost a ton of weight for Requiem for a Dream, and then gained 65 pounds to play John Lennon’s killer in Chapter 27. Did that make losing the weight for Rayon easier, or does knowing what’s in store for you make it more imposing?JARED LETO: I think it becomes easier. You have a greater understanding. To lose a lot of weight like that in a short amount of time like I had, you basically just have to stop eating. You eat raw vegetables and sometimes you just want to chew on something so you find something that has a lot of empty calories. I basically was chewing on shoe-leather, anything that would satiate the hunger a little bit.

How many pounds did you ultimately lose?
I stopped counting somewhere between 30 and 40 pounds – it just wasn’t important to me anymore. If I had more time, I would’ve kept losing weight. I never stopped losing weight; as the film went on, I lost more and more and more.

Was this experience any different than your previous weight transformations?
I did wake up a couple of times a little concerned. Heart pounding, sweating a little much, my temperature running a little too hot and just that trying to catch my breath sort of thing. I hadn’t felt that in my past.

You were Rayon from the moment you stepped on set, never once leaving character. Was the cast aware that was your plan?No, I don’t think they knew because I could see people were– it took them a moment to absorb what was happening. We never discussed things like process or losing weight. Nobody ever talked to me about that.

I get the impression that you have an uncomfortable relationship with fame, that you almost don’t trust it when it’s bestowed so easily, and that mistrust has played a role in some of your career decisions.
I think that’s an accurate statement. In the very beginning, fame can make you feel good when someone comes up and talks to you and says they love what you do. In the beginning, I was confused by that because I thought I had a little bit of a guilt complex. I go, “It’s making me feel good.” That shouldn’t make me feel good. From that very early time, I just shut it down. I never let it affect the way I feel, good or bad.

Did that convince you to put the brakes on a movie career that could’ve gone in a different direction?
Yeah, I think so. I could’ve pursued opportunities that were there that were more traditional, more obvious, more financial rewarding.

Like playing the leading man in a romantic-comedy or something.
Yeah, those opportunities came and went. They were always there. But you just got to do what interests you. I don’t think I’d be very good taking on a film that I wasn’t incredible passionate about. I’m not interested in making the most; I want to make the most interesting.

The last movie you made before Dallas Buyers Club was Mr. Nobody, which you filmed in 2007 and is only now just coming out in theaters, no doubt to ride the wave of Dallas Buyers Club. Had you given up on movies for a while?
There wasn’t a moment where I sat down and had a cry about it, but Mr. Nobody was a really special project and we all worked real hard on it. You can have all the best intentions and work really hard and sometimes it just doesn’t come together. That’s the risk that you take when you make independent film.

Did that experience influence your decision to step back from movies?
Maybe. It’s not like I didn’t have a love or passion for film, but it was interesting to walk away for five or six years not because I didn’t have opportunities but because I was pursuing other ones [in music.]

Yeah, some younger people I met at a recent Thirty Seconds to Mars concert hadn’t seen your movies. They knew you only through your music.
It’s funny. One of my friends noted the abundance of articles [about Dallas Buyers Club] that say, “Musician Jared Leto…” Or “rocker Jared” or “frontman this or that” – that’s the first thing they start with. What a bizarre and incredible thing; I became a musician who acts rather than an actor who makes music.

For more on Jared Leto, including his amazing meeting with director Jean-Marc Vallée that earned him the role of Rayon, pick up this week’s Entertainment Weekly, on newsstands Friday.